RU2555192C1 - Method of underwater situation coverage - Google Patents

Abstract

FIELD: physics.SUBSTANCE: proposed method comprises circular irradiation of probing signals by searcher submarine sonar and reception of echo-signals reflected from targets by receiving antenna with static fan of direction characteristics. Placing of automatic a network of sonars by traditional methods, for example, from aircraft, at the boundary of searcher submarine sonar vision zone. Arrival of direct probing signal and arrival of echo-signal reflected from underwater target are recorded, which is done to define the signal lag, hence, the distance to underwater target and direction of its arrival. Then, distance and direction are encoded by three-digit code of each and transmitted to searcher submarine sonar receiving stage. This allows the searcher submarine to observe the target outside the sonar range, hence, to increase the underwater situation coverage zone. Data transmission from independent automatic sonar to submarine occurs solely in case the automatic sonar classifies the detected target as the submarine.EFFECT: enlarged coverage zone, simplified development of independent automatic sonar system.2 dwg

Description

The invention relates to the field of hydroacoustics and can be used to provide a search for submarines in specified areas of the oceans.

A general trend in military shipbuilding is a significant reduction in the noise level of modern submarines (PL) and, as a result, an increase in the secrecy of their military operations. Detection ranges of low-noise submarines by passive modes of sonar complexes (SAC) decreased from tens to units of kilometers. The increase in the size of the receiving antennas does not give a significant increase in efficiency to the noise-sensing modes of sonar complexes. Therefore, to illuminate the underwater situation in large areas, it is necessary to attract a huge number of search forces and means, which becomes an insoluble problem for the navy [1].

The anti-submarine forces of the leading maritime states solve the problem of combating low-noise submarines in the context of the general concept of creating a unified information environment in combat zones by using rapidly deployed, multi-element lighting systems for underwater conditions, the so-called network-centric systems [2].

The underwater lighting system provides the command with a complete picture of the underwater situation in the war zone and provides target designation to designated anti-submarine forces. Any low-noise submarine is detected when elements of the lighting system of the underwater environment get into the coverage area.

There is a method of illuminating the underwater environment by deploying in a given area a system of autonomous sonar stations (AGAS) for detecting moving objects [3]. This system is one of the elements of the underwater lighting system and is a set of autonomous receiving stations for the detection and classification of underwater objects with the transmission of information via radio or sonar channel. The system is deployed either in the area of anticipated enemy submarine actions, or in the form of a line to control underwater space in the direction of the probable enemy movement. One set of the AGAS system includes several dozen stations installed at anchors at depths of several hundred meters. The setting method does not differ from the known methods [4] for setting up sonar buoys, for example, from anti-submarine aircraft or surface ships. AGAS functioning time - up to 6 months. AGAS solves the problem of detecting, classifying and determining the direction to the target in the noise-detecting mode and transmitting this information to the observer ship. For this, AGAS is equipped with a directional passive antenna and a radiator for transmitting information through the sonar channel. Other autonomous hydroacoustic stations of a similar method for lighting underwater conditions are known [5, 6].

The disadvantage of the method of lighting the underwater environment using these devices is the small detection range in the noise detection mode, and to control a large water area requires setting up a large number of stations to ensure the required efficiency of the lighting system underwater conditions.

There is a method of illuminating the underwater environment by quickly deploying special vessels in certain areas of the oceans, for example, Victories, armed with sonar AN / UQQ-2 (SURTASS) [7]. These surface ships belong to the class of vessels for long-range sonar observation (NK DGN).

The method of lighting the underwater environment is to organize a search for submarines in a given area when the hydroacoustic station is in noise-detecting mode. GAS AN / UQQ-2 uses a 1220 m long flexible towed antenna (HBA) that can be pulled aft on the 1830th cable and towed in the depth range (150-450) m. This underwater lighting system was effective while noisy submarines were quite large and the detection range reached 200 km.

However, due to the decrease in the noise of submarines in recent decades by several times, their detection ranges in the passive mode have decreased to units of kilometers. In this regard, NK DGN began to apply an active-passive method of lighting the underwater situation, which consists in using a towed emitter in the SURTASS system.

The disadvantages of this method are:

- low search efficiency of submarines in this way due to the small detection range in the passive mode;

- fragmentation of the field of view in the active-passive mode, forming around the receiving antenna and having the largest detection range in the direction perpendicular to the GPBA line;

- due to the lack of secrecy of the NK DGN there is a high probability of its destruction by the opposing side.

The closest set of features to the proposed method is a method of lighting the underwater environment, which consists in the fact that the submarine armed with a sonar system is additionally equipped with a rapidly deployable multi-element sonar system. Such a system, for example, is the ADS (Advanced Deployable System) system, which is a bottom fiber-optic sonar array [8] up to 20 km long, covertly installed in a given area by a search submarine, for example, of the Virginia type. At the same time, a relatively flat bottom surface and depth of the sea are required, which allows installation divers to work. Using the ADS system, they detect targets, classify them and determine the coordinates of the targets when it is in passive mode, and when detected, turn on the active mode to determine the coordinates of the target. In the active-passive mode of operation, the ADS emits a sounding signal from stationary bottom emitters installed at a distance of 2-3 miles from the ADS axis. The design of the emitter includes an active antenna part having a small positive buoyancy, and power supplies and generators placed in the anchor device. Power supplies have a limited capacity, so the radiation is produced occasionally only after the establishment of hydroacoustic contact in the noise direction finding mode.

Data on the underwater environment, obtained by ADS, is transmitted via an optical cable to the submarine, where they are integrated with the data of the submarine hull.

According to the test results, it was recognized that the method of lighting the underwater environment, based on the interaction of the SAC submarine and the ADS system, provides the submarine with an increase in the efficiency of lighting the underwater environment through the use of an external sonar system.

The transmission of data on the underwater situation to a surface ship or aircraft is carried out over the air.

The disadvantages of the method of lighting underwater conditions using the ADS system are:

- a relatively low detection range of the system, because the main way to view is the passive mode, and the active mode is used to measure the distance to the target according to the primary detection in the passive mode;

- limited time use of the active mode due to the limited electrical capacity of the power supply;

- stringent requirements for the installation area of the remote sonar antenna on the topography and depth of the place, consisting in the need to install the bottom system on a flat bottom surface and the ability of divers to work at a given depth;

- the technological complexity of deploying an antenna array and radiator, requiring the use of up to 3 submarines and gliders and up to ten installation divers from the board of the submarine and leading to a reduction in the ammunition stock of the submarine, due to the need to load ADS and system modules in missile silos and torpedo tubes technological equipment;

- the difficulty of maneuvering the search submarine when receiving data from ADS via fiber optic cable.

The technical result from the use of the invention is:

- expanding the coverage area of the underwater environment by searching for the enemy’s submarine with the sonar SAR of the search submarine using an external sonar system, which is justified in solving the problem of preventing the enemy from penetrating through specified lines or in protected areas;

- a significant simplification of the deployment technology of the remote sonar system and reduced requirements for the AGAS installation areas in terms of bottom topography and sea depths.

To ensure the claimed technical result, a method of lighting an underwater situation, including searching and detecting an enemy submarine, followed by measuring the distance to it by omnidirectional radiation of sounding signals, receiving noise and reflected signals from an enemy submarine, processing received signals, classifying an enemy submarine, determining it coordinates and transmitting the received information to the search submarine (PL), and the reception of noise and reflected signals from the submarine enemy ki produce a remote multi-element sonar system in the area of the likely location of the enemy submarine, and omnidirectional radiation of sounding signals is produced from a point on the axis of the remote multi-element sonar system, new features have been introduced, namely: as a remote multi-element sonar system in the region of the likely location of the enemy’s underwater target using the traditional method, for example, from airplanes [4], a single- or multi-layer network is set from active-passive autonomous sonar stations (AGAS) installed on anchors with disjoint viewing zones and forming each j spatial channels, the sounding signals are produced by the sonar GAK of the search submarine located in the center of the network from the AGAS located at a distance from the search submarine exceeding the range of its sonar , using a direct probing sonar signal received by the AGAS, a counter is started that counts the time t until the AGAS receives an echo from the underwater target, after which the meter stops and at time t determine the distance from Agas to underwater targets r _Agas, by number of spatial channel Aghasi determine the bearing to the underwater target and, if it is classified in Agas like a submarine, information on the range and bearing of underwater enemy boat coded and coded information to re-emit in the direction of the search submarine, the receiving path of its sonar receives an encoded signal and displays decoded information about the distance and bearing to the enemy submarine on the sonar indicator HAK search th sub.

Thus, the introduction of a remote multi-element sonar system in the underwater lighting system allows increasing the viewing area of the sea space by a search submarine, simplifying the technology of its deployment and expanding the list of areas of the World Ocean where it is possible to set a remote sonar system due to the removal of restrictions on the bottom topography and the depths of the sea.

The invention is illustrated in figures 1 and 2, where figure 1 shows a block diagram of the interaction of a separate AGAS and sonar submarine, and figure 2 shows the location of the search submarine relative to the AGAS network and their corresponding viewing areas that form the FOSS zone.

Each AGAS (figure 1) includes a receiving passive directional antenna 1 connected to a device 2 for forming a fan of directivity characteristics, at the output of which j spatial channels are formed, each of which is connected to its receiving path containing a filter selector 3 tuned to the direct reception band or the reflected signal of the sonar HAK PL, detector 4, integrator 5, classifier 6, threshold device 8, distance meter 9, distance determination unit 11, distance code generation unit 12, determination unit for board 13, the block generating the direction code 14, key 7. The outputs of all j receiving paths are connected to the corresponding inputs of the j-channel radiation control unit of the code signals 15 connected in series with the code signal bank 16, the generator device 17 and the emitter 18.

The sonar mode of the sonar complex includes a transmitting path with a radiating antenna 24 and a receiving antenna of sonar mode 19 connected to a multi-channel receiver 20. The output of each receiver 20 is connected to a threshold circuit 21 and an indicator 23. From threshold circuit 21, code signals are transmitted to decoder 22, from the output of which the distance and bearing parameters to the target relative to the AGAS are received on indicator 23.

The proposed method of lighting underwater conditions, implemented by the flowchart (figure 1), operates as follows.

The transmitting path with the radiating antenna 24 of the sonar hull mode of the submarine submarine emits an omnidirectional sounding signal, which, provided that the enemy’s submarine is in the viewing zone of the sonar mode of the sonar complex of the search submarine, is reflected from the enemy submarine and enters the sonar receiving path 20 in the form of an echo the sonar complex of the search submarine is processed, for example, as described in [9], and the results in the form of distance and direction to the target are displayed on indicator 23.

If the enemy’s submarine is outside the range of the sonar sonar complex sonar complex of the search submarine, the direct sounding signal of the sonar sonar complex is transmitted to the directional receiving antenna 1 of the autonomous sonar station connected to the fan-forming device of directional characteristics 2, at the output of which j spatial channels are formed, each of which is connected to its receiving path containing a filter preselector 3, matched in the frequency band with the signal sonar scrap HAK PL, the direct probe signal detected in the filter is detected by device 4, integrated by integrator 5 and fed to threshold device 8, where a signal that exceeds the threshold and is a direct sonar signal starts the distance meter 9. The AGAS network can be set outside the range of the mode sonar SAR search submarine in several layers (figure 2).

The echo signal reflected from the underwater target is fed sequentially to the directional receiving antenna 1 of the autonomous sonar station, driver 2, directivity filter 3, detector 4, integrator 5, threshold device 8, and to the distance meter 9, stopping it, and the measured time t between the start and stop of the distance meter, 9 enters the distance determination unit 11, where t is multiplied by half the speed of sound s / 2 and thus the distance value from AGAS to discharge targets r _Agas, wherein the distance value is rounded to an integer value and is translated into a binary three-digit code at block 12, known, for example, in [10], together with the threshold device 8, a signal arrives at a determination unit areas 13, known for example from [ 11], and then to the block generating the direction code 14 [10], where it is translated into a binary three-digit code, which ultimately allows you to transfer from AGAS to the search submarine eight range values with an accuracy of 1 km and eight direction values with an accuracy of 45 °, simultaneously from fil Trace of preselector 3, the echo signal arrives at classifier 6, the operation of which is known from [12], and if the target is classified as a submarine, a signal opens to open key 7 from the output of the classifier and the generated distance and direction codes from blocks 12 and 14 are sent to emission control unit code signal 15, the operation of which is known from [13], wherein, in accordance with the received codes from the bank code signals 16 is selected to emit tones codewords with frequencies f ₁ and f _2, separated in frequency with the probe Sig GL mode scrap. These signals are transmitted sequentially to the generator 17 and sonar emitter 18, which emits into the water a set of six signals at frequencies f ₁ and f ₂ , three of which transmit information about the distance and three about the direction to the target. A sequence of six emitted signals is received by the antenna 19 and transmitted to the multichannel receiver 20 of the HAC sonar mode, from which the sequence of six direct signals filtered by the filter bank with frequencies f ₁ and f ₂ from the AGAC is supplied to the threshold device 21, and for these signals compensation the effect of its own Doppler, in a manner known from [13], and then a sequence of 6 tones in decoder 22, the operation of which is also known from [10], is converted to Bearing and distance of the opponent relative AGHASI PL, which are transmitted in the form of a landmark to be displayed on the display submarine sonar search HOOK.

The following example illustrates the increase in the lighting efficiency of the underwater environment when implementing the proposed method, which is expressed in the increase in the area of the underwater space being controlled.

As an example, calculations and comparisons of the area of illuminated underwater space formed by the SAR review areas by the search submarine and the AGAS network, and the area illuminated by the ADS system are given, which makes it possible to evaluate the effectiveness of the proposal.

Calculations are performed for the following initial data.

A. General input.

Hydroacoustic conditions - Barents Sea, winter, sea state 3b.

The radius of the equivalent sphere of the submarine is R = 10 m.

The reduced interference level at the input of the receiving antennas P _n = 10 ^-3 Pa / Hz ^0.5 .

B. Parameters of the sonar SAR search submarine.

The emitting antenna HAC has the shape of a cylinder with a height of h _and = 1 m; working frequency - 3 kHz; the duration of the probe signal T = 1 s; the value of sound pressure during radiation is 150 kPa.

The receiving antenna HAC has the form of a cylinder with a diameter of d _p = 8 m, a height of h _p = 4 m; reception is carried out by a static fan of directional characteristics; the concentration coefficient γ _{p of the} receiving antenna at the operating frequency is γ _p = 720. The threshold signal-to-noise ratio for voltage at the output of the receiving path k _β = 10.

B. Parameters of AGAS.

A system of 5 AGAS located on one straight line is used. The height of the receiving antenna AGAS - 1 m. The concentration coefficient of the antenna at the operating frequency is γ _p = 36. The distance between the AGAS is equal to twice the target detection range of one AGAS. The distance from the search submarine to the AGAS system is equal to the range of the HAC submarine in active mode for the specified conditions.

D. Parameters of the ADS used in the prototype method in the GL mode.

The radiating antenna has the shape of a cylinder with a height h _and = 1 m; working frequency - 3 kHz; the duration of the probe signal T = 1 s; the value of sound pressure during radiation is 15 kPa. The distance of the radiating antenna from the receiving antennas is 3 miles.

The receiving antenna implements ADS reception of echo signals in five portions, each length of 0.9 km (XH wherein the solution is 3 ^0). The distance between the centers of the plots is 3.875 km. The concentration coefficient γ _{p of} each section at a frequency of 3 kHz is equal to γ _p = 36.

To calculate the search area, a Matlab language program was used, based on the sonar equation [14], developed at Okeanpribor Concern OJSC for a multistatic active sonar system, the methods of which are described in [15].

Calculation results.

The proposed method, based on the use of a system including a sonar HAK PL and an AGAS system, provides a total detection area of 7,500 km ² .

The prototype method based on the use of the ADS system provides a detection area of 1,400 km ² .

Thus, for the considered example, the proposed method provides a gain in the size of the detection area equal to 5.3. In addition, the proposed method greatly simplifies the deployment technology of the remote sonar system and, accordingly, allows to reduce costs and time. The proposed method allows you to deploy remote sonar system in areas with complex bottom topography and great depths (up to several hundred meters).

Thus, based on the above example, we can assume that the claimed technical result, which consists in increasing the controlled area of the underwater space through the joint use of the search aircraft submarine and the AGAS network, simplifying the deployment technology and reducing the requirements for the installation areas, has been achieved.

Information sources

1. Naval Forces, 2003, S. Ort, P. Berens and P. De Theije "From low frequency active sonar to net Ecentric underwater warfare: Remedy for silent subs" v.24, No. 5, pp. 41-48.

2. Digest of the foreign press. Navy and shipbuilding. The development of network-centric submarine detection tools. SPb., Central Research Institute named after Academician A.N. Krylova. No 52, 2009

3. Marine electronics. Quick reference. SPb., Ed. Polytechnic. 2003, pp. 186-188.

4. Internet site http://aviation.gb7.ru/il-38.html. 2014 year

5. Patent for invention 2427005. Autonomous sonar module. 2006 year

6. Patent for invention 2427004. Autonomous radio-hydroacoustic station. 2009 year

7. "Foreign military review." 09.1995.

8. Jane's Defense Weekly, 2003, v. 39, No. 26, p. 6.

9. B.A. Zaraisky, A.M. Tyurin. The theory of sonar. L., VMA. 1975 p. 390-392.

10. Internet site: radioelhribor.ru/shifratoryi-i-deshifratory.html. 12/25/2013.

11. G.V. Loskutova, K.I. Polkanov. Spatial-frequency and frequency-wave methods for the description and processing of sonar fields. SPb., "Science", 2007, pp. 136-140.

12. Patent for invention No. 2473924. A method for detecting and classifying a signal from a target. 2011 year

13. Vyong Tuan Hung. Improving the noise immunity of the transmission of code information via the hydroacoustic communication channel. The dissertation for the degree of candidate of technical sciences. SPb., LETI., 2005.

14. Yu.S. Kobyakov, N.N. Kudryavtsev, V.I. Tymoshenko. Design of sonar fishing equipment. L., Shipbuilding. 1986, pp. 74-76.

15. I.S. Shkolnikov et al. Issues of accuracy in determining the coordinates and parameters of target movement in mono- and multistatic active sonar modes. Scientific and technical collection "Hydroacoustics". Issue 17 (1). St. Petersburg: Science, 2013, pp. 61-72.

Claims (1)

A method of lighting an underwater environment, including searching and detecting an underwater target, followed by measuring the distance to it by omnidirectional radiation of sounding signals, receiving noise and reflected signals from an underwater target, processing received signals, classifying an underwater target, determining its coordinates and transmitting the received information to a search underwater a boat (PL), moreover, the reception of noise and reflected signals from an underwater target is carried out by a remote multi-element sonar system in the area of probable driving under water of the enemy’s boat, and omnidirectional radiation of sounding signals is produced from a point on the axis of the remote multi-element sonar system, characterized in that, as the remote multi-element sonar system in the area of the likely location of the enemy’s submarine by the traditional method, for example, from aircraft, one or a multilayer network of active passive autonomous sonar stations (AGAS) installed at anchors in a passive mode with disjoint viewing areas and each spatial channel forming j, the radiation of the probing signals is produced by the SAR sonar of the search submarine located in the center of the network from the AGAS, located at a distance from the search submarine exceeding the range of its sonar, using the direct sounding sonar signal received by the AGAS, the counter counting the time t until this AGAS receives an echo from the enemy’s submarine, after which the counter is stopped and the time t determines the distance from the AGAS to the enemy’s submarine r _agas , by The measurement of the AGAS spatial channel is determined by the bearing on the underwater target and, if the submarine target is classified as the enemy’s submarine, the distance information and the bearing on the enemy’s submarine are encoded and the encoded information is re-emitted in the direction of the search submarine, the encoded signal is received by its receiving path and displayed decoded information about the distance and bearing on the enemy submarine on the indicator of the sonar HAK search submarine.

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